A deferred annuity is an insurance contract that exchanges a lump sum payment, or series of payments, for a guaranteed delayed future stream of income, installments or lump sum. Money inside the contract accumulates tax-deferred until it’s withdrawn. Returns can be variable (that is, based on market performance) or fixed. Savers sometimes use annuities to supplement income from their pension plan or Social Security. All annuity guarantees are subject to the claims-paying ability of the insurer issuing the contract, so it’s important to look closely at the strength and stability of the insurance company you’re considering.